This invention relates generally to communication transmissions and more particularly to time division multiplex access (xe2x80x9cTDMAxe2x80x9d) transmissions.
Transmission of data within a communication system is known to utilize one of a plurality of transmission schemes. Such transmission schemes include time division multiplexing (xe2x80x9cTDMAxe2x80x9d), frequency division multiplexing (xe2x80x9cFDMAxe2x80x9d), quadrature amplitude modulation (xe2x80x9cQAMxe2x80x9d), etc. In a communication system that transports data in a TDM manner, each connection, i.e., communication, receives one or more time slots within a frame of time slots. Accordingly, each device transmitting data via a connection monitors the communication system timing to determine when its time slot, or time slots are active. When a time slot is active, the device may transmit its data in its allocated time slot.
In such a communication system, a device may be an end-user such as a telephone, computer, facsimile machine, video telephone, a server, a router, or a private branch exchange (xe2x80x9cPBXxe2x80x9d). Additionally, switches that comprise a communication system network also transport data utilizing a TDM scheme. For example, in an ATM wireless communication system, an ATM network is coupled to a base station which transceives data over a wireless communication path with network interface units. The data transmitted over the wireless communication path is formatted in accordance with the TDM formatting. As such, each network interface unit that is supporting a communication, i.e., connection, for its plurality of end-users, maintains timing information to determine when the particular time slot for each connection is to occur.
As one can imagine, as the number of connections accessing time slots increases, the management of time slot allocation becomes more complex. In current implementations, a resource manager allocates time slots on a per request basis. The requests, which are generated by an entity which has data to transport and therefore requires a communication path to be established, include the identity of the requesting entity and an amount of bandwidth desired. Based on this information, the resource manager allocates resources, including time slot allocations. The resource manager, at one level or another, monitors the transmission to determine when the parties no longer need the allocated resources. Such a determination may be made by detecting an end of message within data packets transmitted, or some like indication. Upon making this determination, the resource manager flags the resources, including the time slots, as available such that they may be reallocated for another connection.
Due to processing limitations, the resource manager rarely is able to reallocate a time slot in a succeeding frame upon detecting it is available. As such, that particular time slot resource is unused and wasted for a given frame. In addition, as the number of connections managed by the resource manager increases, the processing resources needed to perform the resource management increase accordingly. Therefore, the resource manager performs a substantial amount of processing and, despite the substantial amount of processing, time slot resources are often wasted for one or more frames.
Therefore, a need exists for a method and apparatus that assigns time slots in a TDMA transmission with reduced processing requirements and with minimal loss of time slot resources.